Time travel movies where they’re able to permanently change things for the better and have a happy ending

I appreciate that the moral of a lot of time travel movies is that you can’t change the past.
Doing so will either permanently destroy the future, or your actions are tragically the cause of the future you were trying to prevent.

I want to watch a time travel movie where people are able to go back in time and fix or change something for the better and it ends up happy for them.